History A brief overview of the history of cement around the year 700 BC the Etruscans used pozzolan and lime mixture to make a mortero.Ya in the year 100 BC the Romans used mixtures of lime pozzolan for concrete compressive strength of 5 Mpa.Hasta 1750, just use lime mortars and pozzolanic materials (diatomaceous earth, flour, brick etc).. By 1750-1800 are investigated mixtures caliza.Smeaton calcined clay and compared in 1756 with the appearance and hardness of Portland stone to the south of England. 40 years later, Parker cement factory then natural to apply the term "cement" (previously interpreted as "caement" "any substance capable of improving the properties of others). Vicat explains in 1818 in a scientific manner the behavior of these" "binders". In 1824, Aspdin patented portland cement giving the name for commercial reasons, because of its color and hardness that remind you of Portland stone. Until the advent of self-hardening hydraulic mortar, the mortar was prepared in a mortarium (pan mortar) for percussion and tear, such as in the chemical industry and the years 1825-1872 farmacéutica.Entre appear first cement factory in England France and Germany. 1880, studied the hydraulic properties of slag high horno.En in 1890 appeared the first cement factory España.es 1980, there are 1,500 factories producing about 800 million tons / year . Today cement is the glue or "binder" cheaper than known. Properly mixed with water forms aggregates and concrete, artificial amorphous rock able to take more varied forms with a performance very important mechanical compression. The tensile strength can be improved with the use of reinforcement (reinforced concrete).
Types of cement
have established two basic types of cement: clay
Source: derived from clay and limestone in proportion 1 to 4 or so;
pozzolanic Source: pozzolan cement can be organic or volcanic origin.
There are several types of cement, different in composition, its resistance and durability, and therefore by their targets and uses.
From the chemical point of view is generally a mixture of calcium silicates and aluminates, obtained through the baking of limestone clay and sand. The material obtained, very finely ground, once mixed with water is hydrated and gradually solidifies. Since the chemical composition of cements is complex, specific terminology used to define the compositions.
The
Portland cement Portland cement is the type of cement used as binder for the preparation of concrete or concrete.
was invented in 1824 in England by Joseph Aspdin constructor. The name comes from the similarity in appearance to the rocks found on the Isle of Portland, an island county of Dorset.
The manufacture of Portland cement is given in three phases: (i) Preparation of the mixture of raw materials, (ii) Production of clinker, and (iii) Preparation of the cement.
raw materials for production of Portland are minerals that contain:
calcium oxide (44%), silicon oxide
(14.5%),
aluminum oxide (3.5%), iron oxide
( 3%)
manganese oxide (1.6%).
The extraction of these minerals is done in quarries, which should preferably be close to the factory, minerals and often have the desired composition, however in some cases it is necessary to add clay or limestone or iron ore, bauxite, or residual ore smelters. Scheme
oven
The mixture is heated in a special oven, consisting of a huge cylinder (called a kiln) arranged horizontally at a slight angle, and rolling slowly. The temperature increases along the cylinder up to about 1400 ° C, the temperature is such that the minerals are combined but do not melt or glaze. Section
lower temperature, calcium carbonate (limestone) is separated into calcium oxide and carbon dioxide (CO2). In the high temperature zone of calcium oxide reacts to form silicates and calcium silicates (Ca2Si and Ca3Si). It is also a small amount of tricalcium aluminate (Ca3Al) and Ferroaluminato tetracalcium (Ca4AlFe). The resulting material is called clinker. The clinker can be stored for years prior to the production of cement, provided it does not come in contact with water.
The energy required to produce clinker is approximately 1,700 joules per gram, but because of the heat loss value is considerably higher. This implies a high demand of energy for cement production, and thus releasing a large amount of carbon dioxide in the atmosphere, greenhouse gas.
To improve the characteristics of the final product clinker it adds about 2% of gypsum and the mixture is finely ground. The cement powder obtained is ready for use.
cement composition obtained has a type:
calcium oxide 64% 21%
silica alumina 5.5% 4.5%
iron oxide, magnesium oxide 2.4% 1.6
% 1% sulfate
other materials, including primarily water.
When Portland cement is mixed with water, the product solidifies and hardens in a few hours gradually over a period of several weeks. The initial hardening is produced by the reaction of water, gypsum and tricalcium aluminate, forming a crystalline structure calcium-aluminum-hydrate, estringita and monosulfate. The subsequent hardening and development of internal forces of tension arising from the slower reaction of water with the tricalcium silicate to form a structure called amorphous calcium-silicate-hydrate. In both cases, structures that are formed wrap and set grains of materials present in the mixture. A final reaction produces silica gel (SiO2). The three reactions generate heat.
With the addition of special materials to cement (lime or lime) yields plastic cement that sets faster and more easily workable. This material is used in particular for the external cladding of buildings.
The quality Portland cement shall be in accordance with ASTM C 150.
In 2004, the world's largest producers of portland cement were in France Lafarge, Holcim in Switzerland and Cemex in Mexico. Some cement producers were fined for monopolistic behavior.
clinker formation reactions
1000-1100 ° C3CaO + Al2O3 + SiO2 → 3CaOAl2O3 2CaO 2CaOSiO2 → CaO + Fe2O3 → CaOFe2O3
1100-1200 ° CCaOFe2O3 +3 CaOAl2O3 → 4CaOAl2O3Fe2O31250-1480 ° C2CaOSiO2 + CaO → 3CaOSiO2
will end Composition From 3CaOSiO2
51% 26% 11% 3CaOAl2O3
2CaOSiO
12% 4CaOAl2O3Fe2O3
hydration reactions of hydration reactions, which form the setting process are:
2 (3CaOSiO2) + (x +3) + H2O → 3CaO2SiO2xH2O 3CA (0H) 22 (2CaOSiO2) + (x +1) 3CaO2SiO2xH2O + H2O → Ca (0H) 22 (3CaOAl2O3) + (x +8) + H2O → 4CaOAl2O3xH2O 2CaOAl2O38H2O3CaOAl2O3 + 12H2O + Ca (0H) 2 + 7H2O → → 4CaOAl2O313H2O4CaOAl2O3Fe2O3 3CaOAl2O36H2O + CaOFe2O3H2O
These reactions are all exothermic. The most exothermic hydration 3CaOAl2O3 is followed by that of 3CaOSiO2, and then finally 2CaOSiO2 4CaOAl2O3Fe2O3.
function plaster Plaster or Gypsum is generally added to the clinker to regulate the setting time. Their presence makes the setting is completed in about 45 minutes. Plaster reacts with tricalcium aluminate to form an expansive salt called "ettringite '.3 CaOAl2O3 + 3 (CaSO42H2O) + 26H2O → 3CaOAl2O33CaSO432H2O
Modules Modules are characteristic values \u200b\u200bof each cement or lime, which allow to know in what capacity are, in percentage terms, the various components in the final product. For Portland cement holds: Hydraulic module
silicates Module Module Module students silicic
Cementos Portland
special special Portland cements are cements that are obtained in the same way that the Portland, but have different characteristics because of variations in the percentage of components that form.
Portland The Portland
ferric iron is characterized by a flux of 0.64 module. This means that this cement is very rich in iron. In effect is obtained by inserting mineral pyrite ash or powdered iron. This type of composition therefore involves, in addition to the increased presence of Fe2O3, less 3CaOAl2O3 presence of moisture which is developing more heat. For this reason these cements are particularly suitable for use in hot climates. The best iron cements are those with a low limestone module, in fact they contain fewer 3CaOSiO2, whose hydration produces the greatest amount of free lime (Ca (OH) 2). Since the free lime component is mostly attacked by aggressive water, these cements, containing fewer, are more resistant to aggressive water. White Cement
Unlike ferrous cements, white cements have a high smelters module, about 10. They contain therefore a very low percentage of Fe2O3. EI White is due to lack of iron which gives it a grayish hue to normal Portland and a darker gray ferrous cement. Fe2O3 reduction is offset by the addition of fluorite (CaF2) and cryolite (Na3AlF6) required in the manufacturing stage in the horno.para lower quality type of cement that today there are 4, which are type I 52.5, 52.5 type II, type II and type II 42.5 32.5, also called the pavement) is often added an extra addition of limestone called clinkerita to lower the rate, since normally the clinker ground with gypsum type I would
blended cements cements mixtures are obtained by adding the normal Portland cement and pozzolan other components. The aggregate of these components gives these cements new features that differentiate it from normal Portland.
pozzolanic cement pozzolan is called a fine volcanic ash that lies mainly in the region of Lazio and Campania, its name derives from the town of Pozzuoli, near Naples, on the slopes of Vesuvius. Subsequently it has been widespread volcanic ashes elsewhere. Vitruvius and described four types of pozzolana: black, white, gray and red.
Mixed with lime (in the ratio of 2 to 1) behaves as a pozzolanic cement, and allows the preparation of a good mix capable of forging even under water.
This property enables the innovative use of concrete, as understood by the Romans, the ancient port of Cosa was built with pozzolana mixed with lime just before use and wash under water, probably using a tube, for deposit in the fund without diluted in seawater. The three piers are still visible, with the submerged in good condition after 2100 years.
The pozzolan is a stone of acidic, highly reactive, being very porous and can be obtained cheaply. Pozzolanic cement contains approximately:
55-70% 30-45% clinker Portland pozzolan
2-4% gypsum
Because the pozzolan is combined with lime (Ca (OH) 2), it will less of the latter. But just because the lime is the component that is attacked by corrosive water, pozzolanic cement is more resistant to attack them. On the other hand, as the 3CaOAl2O3 is present only in the component formed by the Portland clinker, pozzolanic cement wash will develop a lower heat of reaction during curing. This cement is therefore suitable for use in particularly hot climates or large castings.
Cement steel
The pozzolan has been replaced in many cases by the coal ash from power plants, smelting slag or residues obtained by heating the quartz. These components are introduced between 35 to 80%. The percentage of these materials may be particularly high, with which originates from silicate material is a hydraulic potential. This should however be activated in an alkaline environment, ie in the presence of OH-ions. It is for this reason must be present for at least 20% of normal Portland cement. For the same reasons that the pozzolanic cement, cement, steel also has good resistance to corrosive water and develops less heat during setting. Another feature of these cements is the high natural alkalinity, which renders it particularly resistant to atmospheric corrosion caused by sulphates.
quick setting cement
rapid hardening cement, also known as "prompt natural or Roman cement," is characterized by initiating the setting within minutes of its preparation with water. It is produced in a manner similar to Portland cement, but with the oven at a lower temperature (1,000 to 1,200 ° C). [2] is appropriate for smaller jobs, fixing and repairs, is not suitable for major projects because they free up time for a good wash. Although you can start setting controlled by natural retardant (E-330) as citric acid, yet if you start the approxmately FRAUD. 15 minutes (temperature at 20 ° C). The advantage is that passing approxmately. Iniado 180 minutes of setting, it achieves high Resistance to compression (from 8 to 10 MPa), so you get great benefit for rapid intervention works and final. There are rapid cement past 10 years, get superior compressive strength some concrete (graphical pass in the 60 MPa). Aluminous cement
Main articles:
aluminosis aluminate cement and alumina cement is produced primarily from bauxite with impurities of iron oxide (Fe2O3), titanium oxide (TiO2) and silicon oxide (SiO2). Additionally, lime is added or calcium carbonate. Aluminous cement, also called "cast concrete", so the oven temperature reaches up to 1,600 ° C and reaches the melting of the components. The cast concrete is poured into molds to form ingots that are cooled and ground to obtain the final product.
aluminous cement has the following composition of oxides:
35-40% calcium oxide
40-50% aluminum oxide
5% silica
5-10% iron oxide
1% titanium oxide
It referred to their real components have:
60-70% 10-15% 2CaOSiO2
CaOAl2O3
4CaOAl2O3Fe2O3
For 2CaOAl2O3SiO2
respect to silica, its presence as an impurity must be less than 6%, because the component that gives rise, ie the (2CaOAl2O3SiO2) is low hydrophilic properties (low water absorption).
hydration reactions H2O → CaOAl2O310H2O CaOAl2O3 +10 (hexagonal crystals) 2 (CaOAl2O3) +11 2CaOAl2O38H2O + H2O → Al (OH) 3 (crystals + gel) 2 (2CaOSiO2) + (x +1) + H2O → 3CaO2SiO2xH2O Ca (0H) 2 (crystals + gel)
While Portland cement concrete is a basic in nature due to the presence of lime Ca (OH) 2, alumina cement is of a substantially neutral. The presence of hydroxide Aluminium Al (OH) 3, which in this case behaves like acid, causing the neutralization of the two components and resulting in a neutral cement.
aluminous cement should be used at temperatures below 30 ° C, so cold weather. Indeed, if the temperature is above the second hydration reaction would change and the formation of 3CaOAl2O36H2O (cubic crystals) and increased production of Al (OH) 3, leading to an increase in volume and could cause the concrete cracks Portland is the best
manufacturing process
Source: derived from clay and limestone in proportion 1 to 4 or so;
pozzolanic Source: pozzolan cement can be organic or volcanic origin.
There are several types of cement, different in composition, its resistance and durability, and therefore by their targets and uses.
From the chemical point of view is generally a mixture of calcium silicates and aluminates, obtained through the baking of limestone clay and sand. The material obtained, very finely ground, once mixed with water is hydrated and gradually solidifies. Since the chemical composition of cements is complex, specific terminology used to define the compositions.
The
Portland cement Portland cement is the type of cement used as binder for the preparation of concrete or concrete.
was invented in 1824 in England by Joseph Aspdin constructor. The name comes from the similarity in appearance to the rocks found on the Isle of Portland, an island county of Dorset.
The manufacture of Portland cement is given in three phases: (i) Preparation of the mixture of raw materials, (ii) Production of clinker, and (iii) Preparation of the cement.
raw materials for production of Portland are minerals that contain:
calcium oxide (44%), silicon oxide
(14.5%),
aluminum oxide (3.5%), iron oxide
( 3%)
manganese oxide (1.6%).
The extraction of these minerals is done in quarries, which should preferably be close to the factory, minerals and often have the desired composition, however in some cases it is necessary to add clay or limestone or iron ore, bauxite, or residual ore smelters. Scheme
oven
The mixture is heated in a special oven, consisting of a huge cylinder (called a kiln) arranged horizontally at a slight angle, and rolling slowly. The temperature increases along the cylinder up to about 1400 ° C, the temperature is such that the minerals are combined but do not melt or glaze. Section
lower temperature, calcium carbonate (limestone) is separated into calcium oxide and carbon dioxide (CO2). In the high temperature zone of calcium oxide reacts to form silicates and calcium silicates (Ca2Si and Ca3Si). It is also a small amount of tricalcium aluminate (Ca3Al) and Ferroaluminato tetracalcium (Ca4AlFe). The resulting material is called clinker. The clinker can be stored for years prior to the production of cement, provided it does not come in contact with water.
The energy required to produce clinker is approximately 1,700 joules per gram, but because of the heat loss value is considerably higher. This implies a high demand of energy for cement production, and thus releasing a large amount of carbon dioxide in the atmosphere, greenhouse gas.
To improve the characteristics of the final product clinker it adds about 2% of gypsum and the mixture is finely ground. The cement powder obtained is ready for use.
cement composition obtained has a type:
calcium oxide 64% 21%
silica alumina 5.5% 4.5%
iron oxide, magnesium oxide 2.4% 1.6
% 1% sulfate
other materials, including primarily water.
When Portland cement is mixed with water, the product solidifies and hardens in a few hours gradually over a period of several weeks. The initial hardening is produced by the reaction of water, gypsum and tricalcium aluminate, forming a crystalline structure calcium-aluminum-hydrate, estringita and monosulfate. The subsequent hardening and development of internal forces of tension arising from the slower reaction of water with the tricalcium silicate to form a structure called amorphous calcium-silicate-hydrate. In both cases, structures that are formed wrap and set grains of materials present in the mixture. A final reaction produces silica gel (SiO2). The three reactions generate heat.
With the addition of special materials to cement (lime or lime) yields plastic cement that sets faster and more easily workable. This material is used in particular for the external cladding of buildings.
The quality Portland cement shall be in accordance with ASTM C 150.
In 2004, the world's largest producers of portland cement were in France Lafarge, Holcim in Switzerland and Cemex in Mexico. Some cement producers were fined for monopolistic behavior.
clinker formation reactions
1000-1100 ° C3CaO + Al2O3 + SiO2 → 3CaOAl2O3 2CaO 2CaOSiO2 → CaO + Fe2O3 → CaOFe2O3
1100-1200 ° CCaOFe2O3 +3 CaOAl2O3 → 4CaOAl2O3Fe2O31250-1480 ° C2CaOSiO2 + CaO → 3CaOSiO2
will end Composition From 3CaOSiO2
51% 26% 11% 3CaOAl2O3
2CaOSiO
12% 4CaOAl2O3Fe2O3
hydration reactions of hydration reactions, which form the setting process are:
2 (3CaOSiO2) + (x +3) + H2O → 3CaO2SiO2xH2O 3CA (0H) 22 (2CaOSiO2) + (x +1) 3CaO2SiO2xH2O + H2O → Ca (0H) 22 (3CaOAl2O3) + (x +8) + H2O → 4CaOAl2O3xH2O 2CaOAl2O38H2O3CaOAl2O3 + 12H2O + Ca (0H) 2 + 7H2O → → 4CaOAl2O313H2O4CaOAl2O3Fe2O3 3CaOAl2O36H2O + CaOFe2O3H2O
These reactions are all exothermic. The most exothermic hydration 3CaOAl2O3 is followed by that of 3CaOSiO2, and then finally 2CaOSiO2 4CaOAl2O3Fe2O3.
function plaster Plaster or Gypsum is generally added to the clinker to regulate the setting time. Their presence makes the setting is completed in about 45 minutes. Plaster reacts with tricalcium aluminate to form an expansive salt called "ettringite '.3 CaOAl2O3 + 3 (CaSO42H2O) + 26H2O → 3CaOAl2O33CaSO432H2O
Modules Modules are characteristic values \u200b\u200bof each cement or lime, which allow to know in what capacity are, in percentage terms, the various components in the final product. For Portland cement holds: Hydraulic module
silicates Module Module Module students silicic
Cementos Portland
special special Portland cements are cements that are obtained in the same way that the Portland, but have different characteristics because of variations in the percentage of components that form.
Portland The Portland
ferric iron is characterized by a flux of 0.64 module. This means that this cement is very rich in iron. In effect is obtained by inserting mineral pyrite ash or powdered iron. This type of composition therefore involves, in addition to the increased presence of Fe2O3, less 3CaOAl2O3 presence of moisture which is developing more heat. For this reason these cements are particularly suitable for use in hot climates. The best iron cements are those with a low limestone module, in fact they contain fewer 3CaOSiO2, whose hydration produces the greatest amount of free lime (Ca (OH) 2). Since the free lime component is mostly attacked by aggressive water, these cements, containing fewer, are more resistant to aggressive water. White Cement
Unlike ferrous cements, white cements have a high smelters module, about 10. They contain therefore a very low percentage of Fe2O3. EI White is due to lack of iron which gives it a grayish hue to normal Portland and a darker gray ferrous cement. Fe2O3 reduction is offset by the addition of fluorite (CaF2) and cryolite (Na3AlF6) required in the manufacturing stage in the horno.para lower quality type of cement that today there are 4, which are type I 52.5, 52.5 type II, type II and type II 42.5 32.5, also called the pavement) is often added an extra addition of limestone called clinkerita to lower the rate, since normally the clinker ground with gypsum type I would
blended cements cements mixtures are obtained by adding the normal Portland cement and pozzolan other components. The aggregate of these components gives these cements new features that differentiate it from normal Portland.
pozzolanic cement pozzolan is called a fine volcanic ash that lies mainly in the region of Lazio and Campania, its name derives from the town of Pozzuoli, near Naples, on the slopes of Vesuvius. Subsequently it has been widespread volcanic ashes elsewhere. Vitruvius and described four types of pozzolana: black, white, gray and red.
Mixed with lime (in the ratio of 2 to 1) behaves as a pozzolanic cement, and allows the preparation of a good mix capable of forging even under water.
This property enables the innovative use of concrete, as understood by the Romans, the ancient port of Cosa was built with pozzolana mixed with lime just before use and wash under water, probably using a tube, for deposit in the fund without diluted in seawater. The three piers are still visible, with the submerged in good condition after 2100 years.
The pozzolan is a stone of acidic, highly reactive, being very porous and can be obtained cheaply. Pozzolanic cement contains approximately:
55-70% 30-45% clinker Portland pozzolan
2-4% gypsum
Because the pozzolan is combined with lime (Ca (OH) 2), it will less of the latter. But just because the lime is the component that is attacked by corrosive water, pozzolanic cement is more resistant to attack them. On the other hand, as the 3CaOAl2O3 is present only in the component formed by the Portland clinker, pozzolanic cement wash will develop a lower heat of reaction during curing. This cement is therefore suitable for use in particularly hot climates or large castings.
Cement steel
The pozzolan has been replaced in many cases by the coal ash from power plants, smelting slag or residues obtained by heating the quartz. These components are introduced between 35 to 80%. The percentage of these materials may be particularly high, with which originates from silicate material is a hydraulic potential. This should however be activated in an alkaline environment, ie in the presence of OH-ions. It is for this reason must be present for at least 20% of normal Portland cement. For the same reasons that the pozzolanic cement, cement, steel also has good resistance to corrosive water and develops less heat during setting. Another feature of these cements is the high natural alkalinity, which renders it particularly resistant to atmospheric corrosion caused by sulphates.
quick setting cement
rapid hardening cement, also known as "prompt natural or Roman cement," is characterized by initiating the setting within minutes of its preparation with water. It is produced in a manner similar to Portland cement, but with the oven at a lower temperature (1,000 to 1,200 ° C). [2] is appropriate for smaller jobs, fixing and repairs, is not suitable for major projects because they free up time for a good wash. Although you can start setting controlled by natural retardant (E-330) as citric acid, yet if you start the approxmately FRAUD. 15 minutes (temperature at 20 ° C). The advantage is that passing approxmately. Iniado 180 minutes of setting, it achieves high Resistance to compression (from 8 to 10 MPa), so you get great benefit for rapid intervention works and final. There are rapid cement past 10 years, get superior compressive strength some concrete (graphical pass in the 60 MPa). Aluminous cement
Main articles:
aluminosis aluminate cement and alumina cement is produced primarily from bauxite with impurities of iron oxide (Fe2O3), titanium oxide (TiO2) and silicon oxide (SiO2). Additionally, lime is added or calcium carbonate. Aluminous cement, also called "cast concrete", so the oven temperature reaches up to 1,600 ° C and reaches the melting of the components. The cast concrete is poured into molds to form ingots that are cooled and ground to obtain the final product.
aluminous cement has the following composition of oxides:
35-40% calcium oxide
40-50% aluminum oxide
5% silica
5-10% iron oxide
1% titanium oxide
It referred to their real components have:
60-70% 10-15% 2CaOSiO2
CaOAl2O3
4CaOAl2O3Fe2O3
For 2CaOAl2O3SiO2
respect to silica, its presence as an impurity must be less than 6%, because the component that gives rise, ie the (2CaOAl2O3SiO2) is low hydrophilic properties (low water absorption).
hydration reactions H2O → CaOAl2O310H2O CaOAl2O3 +10 (hexagonal crystals) 2 (CaOAl2O3) +11 2CaOAl2O38H2O + H2O → Al (OH) 3 (crystals + gel) 2 (2CaOSiO2) + (x +1) + H2O → 3CaO2SiO2xH2O Ca (0H) 2 (crystals + gel)
While Portland cement concrete is a basic in nature due to the presence of lime Ca (OH) 2, alumina cement is of a substantially neutral. The presence of hydroxide Aluminium Al (OH) 3, which in this case behaves like acid, causing the neutralization of the two components and resulting in a neutral cement.
aluminous cement should be used at temperatures below 30 ° C, so cold weather. Indeed, if the temperature is above the second hydration reaction would change and the formation of 3CaOAl2O36H2O (cubic crystals) and increased production of Al (OH) 3, leading to an increase in volume and could cause the concrete cracks Portland is the best
manufacturing process
Cement Factory A wide variety of cements as base raw materials and processes used to produce, which are classified as dry and processes wet processes.
The cement manufacturing process involves four main steps:
Mining and milling of raw materials
homogenization of the raw material
Clinker Production of cement grinding.
The raw material for cement production (limestone, clay, sand, iron ore and gypsum) is extracted from quarries or mines and, depending on the hardness and location of the material, apply certain operating systems and equipment. Once extracted, the raw material is reduced to sizes that can be processed by oil mills.
The homogenization step may be wet or dry, depending on whether you use air or water currents to mix the materials. In the wet process the raw material mix is \u200b\u200bpumped into ponds homogenization and thence to the furnaces that produce clinker at temperatures above 1500 ° C in the dry process, the raw material is homogenized in yards of raw material the use of special machinery. In this process the chemical control is more efficient and energy consumption is lower, since not having to remove the water added to mix the materials, kilns are shorter and less time clinker subjected to high temperatures.
The clinker obtained, regardless of the process used in the homogenization step is then ground with small quantities of gypsum to finally get cement.
Storage cement Cement is a substance particularly sensitive to the action of water and moisture, thus safeguarding their property, they must have some very important precautions include: Immediately after the cement is received in the area of \u200b\u200bworks if bulk cement tanks should be stored in dry, water-proof designed, adequately ventilated and with adequate facilities to prevent the absorption of moisture. If bagged cement must be stored on wooden racks or floor boards, not stack them in tiers of more than 14 bags high for storage of 30 days nor more than 7 bags for storage up to 2 months. To avoid unduly cement age, after arriving in the area of \u200b\u200bworks, the contractor must use the same timing of their arrival. Do not use a bag of cement that has more than two months of storage in the area of \u200b\u200bworks, unless further testing shows that it is in satisfactory condition.
0 comments:
Post a Comment